The present invention relates to a vehicular power plug, and more particularly to a vehicular power plug with adjustable length to meet the allocation requirements in various kinds of vehicles.
Due to the compact size and versatility of the modern electrical appliances, many of them are developed to be suitably used in a vehicle and operatable with the vehicular direct-current power, generally 12 volts. FIG. 1 schematically shows the structure of a conventional vehicular power plug. The vehicular power plug includes a plug portion 11 to be inserted into the cigarette lighter adapter (not shown) of a vehicle, and a connector portion 12 to be connected to an electrical appliance 13. The plug portion 11 and the connector portion 12 have respectively specific configurations for different functions. The connector portion 12, for example, can be a cell phone handsfree car kit, a cell phone charger, a vehicular lamp, a fan, a speaker or a liquid crystal display. In order to be in tune with the position of the cigarette lighter adapter and meet the allocation requirements in various kinds of vehicles, the vehicular power plug is preferably length-adjustable.
Unfortunately, conventional vehicular power plugs have fixed length. If a longer power plug is required, an additional adapter will be required between the plug portion and the cigarette lighter adapter, as shown in FIG. 2A, or between the connector portion and the electrical appliance, as shown in FIG. 2B.
Please refer to FIG. 2A. The additional adapter 20 is mounted to the plug end 211 of the vehicle power plug 21, so the adapter 20 is required to have a plug end 201 with a configuration identical to that of the plug end 211 in order to be inserted into the cigarette lighter adapter in lieu of the plug end 211. The other end 202 of the adapter 20 is designed to match the plug end 211 so that the connection of the ends 211 and 202 prolongs the entire vehicle power plug 20 and 21. Further, the other end 212 of the original vehicle power plug 21 is still for connecting with the electrical appliance.
Now refer to FIG. 2B. The additional adapter 30 is mounted to the connector end 311 of the vehicle power plug 31, so the adapter 30 is required to have a connector end 301 with a configuration identical to that of the connector end 311 in order to be connected with the electrical appliance in lieu of the connector end 311. The other end 302 of the adapter 30 is designed to match the connector end 311 so that the connection of the ends 311 and 302 prolongs the entire vehicle power plug 30 and 31. Further, the other end 312 of the original vehicle power plug 21 is still for inserting into the cigarette lighter adapter.
The above-mentioned adapters 20 and 30 are designed for specifically prolonging the vehicular power plug. In other words, there is no further function associated with the complicated structure of the adapter. The use of such adapters 20 and 30 to just prolong the vehicular power plug is apparently inefficient in manufacturing time and cost. The assembling process is also bothersome.
Therefore, an object of the present invention is to provide a vehicular power plug that is extendable without any additional adapter.
Another object of the present invention is to provide a vehicular power plug with simple length-adjusting mechanism.
According to a first aspect of the present invention, a vehicular power plug with adjustable length for use with a vehicular electrical appliance includes a plug end electrically connected to a vehicular power source for getting a power needed for the vehicular electrical appliance; a connector end electrically connected to the vehicular electrical appliance for transmitting the power to the vehicular electrical appliance; a first sleeve body connected to the plug end for supporting the plug end; a second sleeve body connected to the connector end for supporting the connector end, and slipable relative to the first sleeve body; and a positioning member for changing the relative position between the first sleeve body and the second sleeve body from a first position to a second position in response to an external force applied on the first and second sleeve bodies, and securing the first and second sleeve bodies at the second position when the external force is removed, thereby adjusting the length of the vehicular power plug.
In an embodiment, the positioning member includes a resilent sustaining unit mounted on one of the first sleeve body and the second sleeve body; and a receiving unit mounted on the other one of the first sleeve body and the second sleeve body, and matching the resilent sustaining unit for engaging with the resilent sustaining unit to fix the first and second sleeve bodies at the second position.
In another embodiment, the second sleeve body sleeves around the first sleeve body, and has an inner surface faces an outer surface of the first sleeve body. Meanwhile, the positioning member includes an elastic unit passing through the first sleeve object radially; a first locking-unit attached to the elastic unit and protruding from the outer surface of the first sleeve object; and a second locking unit mounted on the inner surface of the second sleeve body and cooperating the first locking unit to lock the first locking unit in the second locking unit at the second position.
For example, the elastic unit can be a spring passing through a penetrating aperature formed on the first sleeve body in the radial direction. The first locking unit includes two balls respectively attached to two ends of the spring and partially protruding from opposite openings of the penetrating aperature. The second locking unit comprises plural pairs of holes in which each pair of the holes are arranged in opposition on the inner surface of the second sleeve body so as to form two rows of holes. The balls slip against the two rows of holes, respectively, from the first position to the second position in response to the external force, and the two rows of holes match the two balls in size so that the balls are trapped in a pair of the holes when the external force is removed to fix the first and second sleeve bodies at the second position.
Alternatively, the positioning member includes a first locking unit protrudently mounted on the outer surface of the first sleeve body; and a second locking unit mounted on the inner surface of the second sleeve body and cooperating with the first locking unit for locking the first and second sleeve bodies at the second position.
For example, the first locking unit includes a resilent piece with one end fixed on the outer surface of the first sleeve body and the other end as a protrudent free end. The second locking unit includes a series of notches arranged axially on the inner surface of the second sleeve body. The notches matches the protrudent free end for locking the protrudent free end therein.
For another example, the first locking unit includes a resilent arc slice mounted on the outer surface of the first sleeve body, and the second locking unit includes a trench mounted on the inner surface of the second sleeve body. The resilent arc slice slides in the trench in response to the external force.
In a further embodiment, the positioning member includes a first locking unit protrudently mounted on the inner surface of the second sleeve body; and a second locking unit mounted on the outer surface of the first sleeve body and cooperating with the first locking unit for locking the first and second sleeve bodies at the second position.
According to a second aspect of the present invention, a vehicular power plug with adjustable length for use with a vehicular electrical appliance includes a plug end electrically connected to a vehicular power source for getting a power needed for the vehicular electrical appliance; a connector end electrically connected to the vehicular electrical appliance for transmitting the power to the vehicular electrical appliance; a first body connected to the plug end for supporting the plug end; a second body connected to the connector end for supporting the connector end; and a positioning member connected to the first and second bodies for changing an overlapping area of the first body and the second body in response to an external force to adjust the length of the vehicular power plug.
Preferably, the first body and the second body are respectively first cylindrical sleeve and second cylindrical sleeve arranged telescopically.
Preferably, the positioning member includes a resilent sustaining unit mounted on one of the first cylindrical sleeve and the second cylindrical sleeve; and a receiving unit mounted on the other one of the first cylindrical sleeve and the second cylindrical sleeve and matching the resilent element for fixing the first and second cylindrical sleeves at a specific relative position according to the overlapping area.
According to a third aspect of the present invention, a vehicular power plug with adjustable length for use with a vehicular electrical appliance includes a plug end electrically connected to a vehicular power source for getting a power needed for the vehicular electrical appliance; a connector end electrically connected to the vehicular electrical appliance for transmitting the power to the vehicular electrical appliance; a first sleeve body connected to the plug end for supporting the plug end; a second sleeve body connected to the connector end for supporting the connector end, and telescopically moved relative to the first sleeve body; a resilent unit mounted on the first sleeve body; and a receiving unit mounted on the second sleeve body and matching the resilent element, in which a relative position between the first sleeve body and the second sleeve body is changed in response an external force applied on the sleeve bodies, and the relative position is fixed by locking the resilent unit in the receiving unit when the external force is removed.